This application is to obtain partial support for a "Symposium on Cyclic Nucleotide Phosphodiesterases" to be held in H ouston, Texas, on April 15, 16 and 17, 1982. This symposium is the first meeting ever devoted entirely to this enzyme system. The University of Texas Health Science Center at Houston is hosting this event, the first such official undertaking by the Health Science Center. The Steering Committee comprises representatives from The Universityh of Texas Medical School and Graduate School of biomedical Sciences at Houston and the Baylor College of Medicine. Invited partcipants (35) are from the major medical centers across the United States and a few from abroad. The results of the symposium will be published as Volume 16 of the "Advances in Cyclic Nucleotide Research" series and edited by Drs. Strada and Thompson. We anticipate that attendance at this symposium will be enhanced by its immediate precedence to the 1982 FASEB meeting in New Orleans, Louisiana. The Symposium will consist of a three day lecture, discussion, special session roundtable, and poster program on the Biochemistry, Pharmacology, regulation, and clinical implications of this enzyme system which is integrally important to cell growth and cancer and diabetes, as well as normal tissue responses to drugs, hormones and cellular efectors. Besides identifying the central themes of cyclic nucleotide phosphodiesterase regulation, an important aim of the symposium will be the development of a standard nomenclautre by the experts in the field. We are seeking NIH support for the symposium not only to aid in generally ofsetting its costs, but to help us provide for the attendance of students and interested young scientists who might not otherwise be able to attend.